1. Field of the Invention
Example embodiments of the present invention relate to a method of boosting a local dimming signal, a boosting drive circuit for performing the method, and a display apparatus having the boosting drive circuit. More particularly, example embodiments of the present invention relate to a method of boosting a local dimming signal capable of individually driving light source unit blocks, a boosting drive circuit for performing the method, and a display apparatus having the boosting drive circuit.
2. Description of the Related Art
Generally, a liquid crystal display (LCD) apparatus includes an LCD panel displaying an image using optical transmittance of liquid crystal molecules, and a backlight assembly disposed below the LCD panel to provide the LCD panel with light.
The LCD panel includes an array substrate, a color filter substrate and a liquid crystal layer. The array substrate includes a plurality of pixel electrodes and a plurality of thin-film transistors (TFTs) electrically connected to the pixel electrodes. The color filter substrate faces the array substrate and has a common electrode and a plurality of color filters. The liquid crystal layer is interposed between the array substrate and the color filter substrate.
When an electric field generated between the pixel electrode and the common electrode is applied to the liquid crystal layer, the arrangement of liquid crystal molecules of the liquid crystal layer is altered to change optical transmissivity, so that an image is displayed. Here, the LCD panel realizes a white image of a high luminance when an optical transmittance is increased to maximum, and the LCD panel realizes a black image of a low luminance when an optical transmittance is decreased to minimum.
However, it is difficult for the liquid crystal layer to be arranged in a uniform direction, so that light leakage may be generated when the LCD panel displays an image corresponding to a low gray level. That is, it is difficult for the LCD panel to display a fully black image at a low gray level, so that the contrast ratio of an image displayed on the LCD panel may be decreased.
In order to prevent the contrast ratio of an image from being decreased, a method of local dimming a light source has been developed, which individually controls light amounts according to position to drive the light source. In the method of local dimming the light source, the light source is divided into a plurality of light-emitting blocks to control the light amounts of the light-emitting blocks in correspondence with black and white areas of a display area of the LCD panel corresponding to the light-emitting blocks.
Recently, a method of local dimming a light source has been developed, which enhances the luminance corresponding to predetermined light source blocks relative to peripheral light source blocks. The method of local dimming the light source represents a technology which enhances a dynamic contrast ratio with respect to a conventional local dimming method.
However, since the local boosting method is a technology which enhances the luminance of the predetermined light source blocks relative to the peripheral light source blocks, power consumption may be increased when the local boosting method is used.